Occasional reflections on Life, the World, and Mathematics

Guilt by association — you’re friends with a terrible person so you must also be one — is generally recognised as a pernicious logical fallacy. But what should we call this comment by Israeli Foreign Ministry spokesman Paul Hirschson, explaining why Norwegian trauma surgeon Mads Gilbert has been banned from returning to Gaza after he made critical remarks about the Israeli military activities this past summer? Dr Gilbert, he opined, is

not on the side of decency and peace and he’s got a horrible track record. I wouldn’t be surprised if his acquaintances are among the worst people in the world.

In other words, he’s a terrible person, so I’m sure his friends are too. Is this association by guilt?